Spring rains — five inches in Norman over the past week — have restored Lake Thunderbird to normal. Now water levels are edging into the lake’s flood pool.
“There’s no need to panic over getting a little more water in the reservoir,” said Russ Adkins, U.S. Army Corps of Engineers spokesman.
The Corps of Engineers makes decisions regarding flood control and the release of waters from Thunderbird.
“We have to look at it (the lake) as a system,” Adkins said. “If we’re going to get more rains, we can’t let the pool get too full.”
While the National Weather Service reports a flash flood watch through early morning hours today, rain chances were reduced Wednesday from earlier predictions. Partly cloudy skies and 20 percent chance of thunderstorms this morning should give way to a high in the upper 70’s. Fair skies are predicted for tonight.
Adkins said the Corps is not worried about Thunderbird at this time but will monitor the lake level closely through the next few days if rains continue. The lake is meant to hold water and prevent flooding downstream, and is operating as intended.
The flood gates of Norman Dam haven’t been opened in three years. This winter, Lake Thunderbird’s conservation pool was down more than seven feet.
“We’ve got a lot of capacity to store additional rainfall,” said Randy Worden, district manager of the Central Oklahoma Master Conservancy District. “We’ll open them when the Corps of Engineers asks us to open them.”
Whether flood gates are opened depends on circumstances downstream and upstream, as well as anticipated rainfall, Worden said. The Corps also determines how wide to open the gates, which controls how quickly water is released.
“We’d like to carry additional water this summer if possible, but the Corps has to make that determination,” Worden said. “It would help the fisheries and give us more comfort to carry additional water.”
The COMCD manages Thunderbird, which is a U.S. Bureau of Reclamation lake, but the U.S. Army Corps of Engineers does flood control for all U.S. lakes.
Adkins said the Corps is likely to keep Thunderbird high to retain a normal pool level into the hot summer months. If the flood gates are opened, that will not restrict pumping for municipal and industrial uses.
While city leaders hope Norman residents will continue to be water wise, the city ended mandatory water conservation effective today.
“The city sincerely thanks the residents and businesses that were instrumental in helping everyone maintain water supplies during the many days of record low water levels in Lake Thunderbird,” City Manager Steve Lewis said .
In January, with the drought continuing into its third year, the COMCD imposed a mandatory 10 percent reduction to Norman’s allocation of water from Lake Thunderbird. Norman implemented water rationing Jan. 14.
With water levels back to normal, COMCD suspended 10 percent reduction in allocation. Norman also has contracted with Del City to use a portion of its Thunderbird allotment if needed.
Norman Utilities Director Ken Komiske said water customers are encouraged to be water wise this summer.
“When people do start watering their lawns, we hope people will keep good watering practices in mind,” Komiske said. “Watering every other day is better for your yard. It gets the roots established more and it’s better for your wallet.”
In addition to drawing water from Lake Thunderbird, Norman supplements its water supply with wells.
Every spring, well motors are checked and wells are disinfected as a safety measure. Often, however, when Norman buys treated water from Oklahoma City during high-use months, part of the issue is the ability to treat mass quantities of raw water.
“We’re replacing about three and a half miles of 33-inch diameter water line with 48-inch line,” Komiske said. “This will give us greater treatment capacity ... but we are still bound by the annual allocation of water we’re allowed to draw from the lake.”